Commit 2ad67141 authored Jul 11, 2017 by Tushar Dave Committed by David S. Miller Jul 12, 2017

SPARC64: Fix sun4v DMA panic



64bit DMA only supported on sun4v equipped with ATU IOMMU HW.
'Commit b02c2b0b ("sparc: remove arch specific dma_supported
implementations")' introduced a code that incorrectly allow
dma_supported() to succeed for 64bit dma mask even if system doesn't
have ATU IOMMU. This results into panic.

Fix it.

Reported-by: Meelis Roos <mroos@linux.ee>
Signed-off-by: Tushar Dave <tushar.n.dave@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 3b06b1a7

arch/sparc/kernel/pci_sun4v.c

+7 −5

Original line number	Diff line number	Diff line
		@@ -673,12 +673,14 @@ static void dma_4v_unmap_sg(struct device dev, struct scatterlist sglist,
		static int dma_4v_supported(struct device *dev, u64 device_mask)
		{
		struct iommu *iommu = dev->archdata.iommu;
		u64 dma_addr_mask;
		u64 dma_addr_mask = iommu->dma_addr_mask;

		if (device_mask > DMA_BIT_MASK(32) && iommu->atu)
		if (device_mask > DMA_BIT_MASK(32)) {
		if (iommu->atu)
		dma_addr_mask = iommu->atu->dma_addr_mask;
		else
		dma_addr_mask = iommu->dma_addr_mask;
		return 0;
		}

		if ((device_mask & dma_addr_mask) == dma_addr_mask)
		return 1;